Groupon has come under fire from scores of unhappy shoppers in the UAE amid ongoing delivery delays and a customer-service hotline overwhelmed with complaints. The US retail giant, which launched its online deals site in the UAE this year, has received more than 100 messages complaining about its service and has admitted to being overwhelmed by demand. Groupon is the global leader in the online daily deals industry, which specialises in discounts on goods, services and travel. It launched an initial public offering last year and has a market capitalisation of US$14.7 billion (Dh53.99bn). A flood of such sites launched in the Middle East this year, including LivingSocial, which bought out the local start-up GoNabit. But in a widespread consumer backlash against Groupon, UAE residents cite late delivery of goods and a failure by the company to deal with complaints promptly. Many users posted multiple comments on Groupon UAE\'s Facebook wall, where there are currently more than 100 messages critical of its service. \"Groupon seriously needs to clear the backlogs if they want to stay in business,\" wrote one user on Facebook. \"This is really pathetic, backlogs not cleared and new deals are being marketed.\" Groupon says the problem is specific to the UAE, and is because of increased demand for its deals over Christmas. \"Delivery times haven\'t been as fast as we would have liked,\" said Ainsley Duncombe, the chief executive of Groupon Middle East. \"Demand has been up 50 per cent over the festive period. We have had an overwhelming response to our products.\" With scores of UAE residents complaining that they are unable to get through to the company\'s customer service hotline, Mr Duncombe said Groupon had added capacity to deal with inquiries. \"We have increased the number of people that are working on our customer service, and we have also upgraded our telephone lines to take the additional calls that have been coming in,\" he said. \"In addition to that, I personally have been making calls to customers.\" Mr Duncombe declined to specify how many staff Groupon will be adding to deal with the problem, or to quantify the total number of delayed orders. More than one user accused Groupon of deleting negative messages posted to its Facebook wall, although the company denies this. Other customers say they planned to raise the issue with the Ministry of Economy. Groupon acknowledged the problem in a message to consumers posted on Facebook. \"In an effort to bring our customers the best deals out there, we recently started sourcing products from international suppliers … We have had overwhelming response to this and unexpectedly had very big volumes to deal with without being fully prepared,\" the company said. \"In some cases we have missed the delivery deadlines. As a result of this, our phone lines and email accounts have been flooded, limiting our ability to answer all the inquiries at the level we would like to maintain.\"